<template>
  <div class="todo-footer">
    <label>
      <input type="checkbox" v-model='allChecked' />
    </label>
    <span> <span>已完成{{getNum}}</span> / 全部{{todoList.length}} </span>
    <button class="btn btn-danger" @click="deleteAllFinish">清除已完成任务</button>
  </div>
</template>

<script>
export default {
  name: "Footer",
  props:['todoList','setAllChecked','deleteAllFinish'],
  computed:{
    allChecked:{
      get(){
        return this.todoList.every(item=>{
          return item.done
        }) && this.todoList.length !==0
      },

      set(done){
        this.setAllChecked(done)
      }
    },
    getNum(){
      return this.todoList.reduce((p, c) =>{
        return c.done ? p+1 : p
      } ,0);
    }
  }
};
</script>

<style scoped>
/*footer*/
.todo-footer {
  height: 40px;
  line-height: 40px;
  padding-left: 6px;
  margin-top: 5px;
}

.todo-footer label {
  display: inline-block;
  margin-right: 20px;
  cursor: pointer;
}

.todo-footer label input {
  position: relative;
  top: -1px;
  vertical-align: middle;
  margin-right: 5px;
}

.todo-footer button {
  float: right;
  margin-top: 5px;
}
</style>